Leftover Roast Beef Sandwich (Ready in 5 Minutes)

Name: Leftover Roast Beef Sandwich
Prep time: 5 min
Total time: 5 min
Ingredients: 4 teaspoons Butter; 160 g Sourdough bread (about 40 g / 1½ oz per slice); 30 g Spinach; 120 g Leftover roast beef (sliced); 4 teaspoons Horseradish sauce; 24 g Sun-dried tomatoes (about 4g per tomato); 60 g Pickled gherkins (sliced); 100 g Cheddar cheese slices (about 25 g / 1 oz per slice); 40 g Brie (sliced)

This Leftover Roast Beef Sandwich is the perfect way to use up beef from Christmas dinner or a Sunday roast. Tender slices of roast beef, creamy Brie and Cheddar, spicy horseradish, gherkins and sun-dried tomatoes all piled between thick slices of sourdough bread.

A hand holding two large roast beef sandwiches.

It's ready in just 5 minutes, with no cooking needed, and is one of my favourite ways to turn roast dinner leftovers into something that feels like a whole new meal.

I especially love making a sandwich like this after Christmas, when there are always bits of cheese, chutney and other leftovers in the fridge that need using up.

Recipe update: This recipe was originally published on 19 December 2020 and was fully retested in November 2026 to check the preparation time and ingredient quantities. The original recipe still worked well, but I've expanded the instructions, tips and FAQs.

Recipe Overview

The recipe: A cold, no-cook roast beef sandwich with Brie, Cheddar, horseradish and crunchy pickles, served on thick sourdough.
Makes: 2 generously filled sandwiches, using 120g of leftover roast beef.
The key to success: Slice the beef thinly, drain the toppings well and assemble just before serving for the best texture.

Jump to:

Recipe Overview
Why You'll Love It
Ingredients and Substitutions
How to Make Leftover Roast Beef Sandwiches
How to Make the Best Roast Beef Sandwich
Roast Beef Sandwich Ideas and Variations
Serving Suggestions
Storage and Make Ahead
Dannii's Extra Tips
Troubleshooting Guide
Frequently Asked Questions
More Beef Recipes
Recipe
Feedback

Why You'll Love It

Ready in 5 minutes - No cooking needed, just assemble and enjoy.
Perfect for leftovers - A delicious way to use up roast beef from Christmas dinner or a Sunday roast.
Full of flavour - Tender beef, creamy cheese, tangy pickles and spicy horseradish are a brilliant combination.
Easy to adapt - Use whatever bread, cheese and toppings you already have.

Ingredients and Substitutions

All the ingredients needed for this recipe laid out with text overlay labels.

A full ingredients list, along with US Customary and Metric measurements, can be found in the recipe card at the end of this post.

Roast beef - We used leftover slow cooker roast beef, but any cooked roast beef will work. Our slow cooker beef brisket is another delicious option. Thin slices work best, especially for a cold roast beef sandwich.
Bread - We love sourdough because it's sturdy enough to hold all the fillings. Tiger bread, ciabatta or a crusty bloomer would work well too.
Horseradish sauce - A classic pairing with roast beef that adds a lovely kick. If you prefer something milder, try wholegrain mustard, mayonnaise or caramelised onion chutney.
Cheese - We used Brie and Cheddar, which makes this a brilliant way to use up Christmas cheeseboard leftovers. Swiss cheese, Gruyère, Stilton or Wensleydale would also work.
Spinach - Adds freshness and colour. Swap for iceberg lettuce if you want more crunch, or rocket if you like a peppery flavour.
Gherkins and sun-dried tomatoes - These add a tangy contrast to the rich beef and cheese. You could also use sliced pickled beetroot or quick pickled red onions.
Butter - Adds flavour and helps prevent the bread from becoming soggy. You can leave it out if you prefer.

How to Make Leftover Roast Beef Sandwiches

A slice of buttered bread with salad leaves on it.

Butter the slices of sourdough bread, then divide the spinach between two slices.

Slices of roast beef with horseradish sauce added to the sandwich.

Add the sliced leftover roast beef and spread the horseradish sauce over the beef.

Slices gherkins and sun-dried tomatoes added.

Top with the sliced gherkins and sun-dried tomatoes.

Slices of cheddar and brie added to the sandwich.

Add the Brie and Cheddar, then finish with the remaining slices of bread. Cut in half and serve.

How to Make the Best Roast Beef Sandwich

The key to a really good roast beef sandwich is getting the balance of flavours and textures right. You want tender beef, something creamy, a little sharpness and bread that can hold everything together.

For the best texture, slice your roast beef thinly and against the grain. This is especially important when using cold leftovers, as thicker slices can be chewy.

If your beef has been in gravy, let any excess gravy drain off before adding it to the sandwich. You want the beef to be moist without making the bread soggy.

I like this sandwich served cold, straight from the fridge, but you can lightly toast the bread first if you prefer a little extra crunch.

Roast Beef Sandwich Ideas and Variations

One of the best things about this recipe is how easily you can change the fillings depending on what you have.

For a simpler sandwich: Skip the sun-dried tomatoes and use just roast beef, Cheddar, lettuce and horseradish. Sometimes the classic combination is all you need.

For a Christmas leftovers sandwich: Add a spoonful of Christmas chutney, some leftover caramelised onions or a little cranberry sauce. These work particularly well with the Brie and beef.

For extra crunch: Add thin slices of radish, red onion or iceberg lettuce. You could even add a spoonful of coleslaw.

You don't need to include every topping. Choose a few flavours that work well together and let the roast beef be the star.

Serving Suggestions

This leftover roast beef sandwich is filling enough to serve on its own, especially with all that cheese and tender beef. However, if you're serving it for lunch and want something extra on the side, there are lots of options.

For a classic sandwich and crisps combination, try our homemade garlic crisps.

If you want something more substantial, serve it with baked sweet potato chips or our crispy air fryer chips.

For a lighter, crunchy side dish, we love our healthy coleslaw or Greek yogurt coleslaw.

Our watercress salad is another lovely option if you enjoy peppery flavours alongside roast beef.

Roast beef sandwiches on a wooden serving board with potato crisps and a bowl of horseradish sauce.

Storage and Make Ahead

Store: This sandwich is best assembled just before eating, as the bread and salad can become soggy. Store the individual ingredients separately in airtight containers in the fridge.

Cooked leftover roast beef should be cooled and refrigerated within 2 hours of cooking, then eaten within 48 hours or frozen, in line with UK Food Standards Agency guidance.

Make ahead: You can prepare the sandwich fillings in advance and keep them refrigerated. Assemble the sandwiches shortly before serving. If packing one for lunch, keep it chilled in an insulated lunch bag with an ice pack.

Freeze: We don't recommend freezing an assembled roast beef sandwich, as the cheese, salad and other toppings won't freeze well. However, you can freeze leftover cooked roast beef separately to use in sandwiches another day. Defrost it in the fridge and use it within 24 hours.

Dannii's Extra Tips

Slice the beef thinly - Cutting against the grain makes leftover roast beef more tender and easier to eat in a sandwich.
Use sturdy bread - Sourdough or a crusty bloomer will hold the generous filling better than thin, soft sandwich bread.
Avoid soggy sandwiches - Drain the gherkins and sun-dried tomatoes well, and add the fillings just before serving.
Adjust the sauce - Horseradish adds a lovely kick, but you can swap it for mayonnaise, wholegrain mustard or truffle mayo.
Use leftover gravy - A very thin layer of thick gravy can be delicious with the beef. Just don't add too much, or the bread will become soggy.

Two stacks of beef sandwiches with pickles on top.

Troubleshooting Guide

Problem	Likely cause	Fix
The bread is soggy	The gherkins or sun-dried tomatoes are too wet, or the sandwich was made too far in advance.	Drain and pat dry the toppings, and assemble the sandwich just before eating.
The roast beef is tough or chewy	The cold beef has been sliced too thickly or with the grain.	Slice thinly against the grain and add a little extra horseradish sauce or mayonnaise if it's dry.
The sandwich falls apart	Too many fillings or bread that's too soft to hold everything together.	Use thick sourdough, spread the fillings evenly and secure with a cocktail stick before cutting.

Frequently Asked Questions

Can you eat leftover roast beef cold in a sandwich?

Yes, as long as the beef was thoroughly cooked, cooled safely and stored in the fridge within 2 hours of cooking. Leftover roast beef should be eaten within 48 hours or frozen. Cold roast beef is particularly good in sandwiches when sliced thinly.

Can I make a hot roast beef sandwich instead?

Yes. For a warm version, you can toast the bread and melt the cheese. If you also reheat the leftover beef, make sure it is steaming hot throughout and only reheat it once. Serve immediately.

Why is my leftover roast beef a little dry?

Slice it as thinly as possible and add a little extra horseradish sauce or mayonnaise. You could also serve some warm gravy alongside the sandwich for dipping, rather than pouring it over the bread.

Can I use shop-bought roast beef?

Absolutely. Thinly sliced roast beef from the supermarket or deli works well if you don't have leftovers. Just follow the storage and use-by instructions on the packaging.

More Beef Recipes

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